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Hey, I'm new to the site. I have a 2002 Saturn SL 5M.

I've been using many of the hypermiling techniques here since last summer. I started accelerating more gently, cruising at 90km/h when possible, DWB, DWL, engine braking and light timing. I've been keeping fuel logs since we bought the car and I have my own spreadsheet for calculations and comparison. Fuel economy increased from 6.5L/100km the previous summer to 5.5L/100km.

This week I've been reading a lot on this site and I've done a few more things. I pumped my snow tires up to the sidewall max of 35psi. I've been gliding with the engine on whenever possible and doing pulse & glide (but only on downhills that aren't steep enough to keep speed up). I don't know how much these have affected my mileage yet because the temperature is changing as spring arrives and I'm putting a new set of all-season tires on tomorrow. They will be inflated to max sidewall pressure.

I have a few questions that I'm sure many of you have data on.

How much does increasing tire pressure of snow tires affect the grip on snow and ice? There's less rubber on the road, so there are fewer biting surfaces to get grip on the snow.

What is the best speed to cruise at? My commute consists of mostly 80km/h and 90km/h roads, both of which I go 90-95 on. I don't use P&G. Most of the information I've found about cruising speed has been for hybrids. The car has good aerodynamics though, so I'm wondering if I might be better off at 105km/h.

I'm also wondering about acceleration. I was lucky to be able to find the Brake Specific Fuel Consumption map for my engine.
http://img172.imageshack.us/img172/6017/saturn19ldohcbsfcmap.png
This tells me that I'm probably best off with my foot down approximately 3/4 of the way, and shifting no later than 2500rpm. Is this right? Does engine load relate directly to accelerator position? I have to admit that I like the idea of accelerating with high load and low revs. It's fun and I'm no longer lagging behind traffic when the light turns green. I hope I'm right :)

Also, my commute consists of going up and down the Niagara Escarpment. It's usually on one of the highways instead of the steep street accesses, so it's about 2km steady uphill, approximately 300m in elevation change. What's the best way to tackle this?

I'm looking forward to seeing how the recent changes will affect my mileage, as well as refining it further.

Yes. Follow that BSFC chart, but with an emphasis on the lower end of rpm. Aim for 2,000 more than for 2,500.

Pedal position roughly relates to load, but at lower rpm, it takes a bit less pedal to reach the same load. Aim for maybe 1/2 throttle and ramp up to 3/4 as the rpm increases.

For that long climb, aim for rpm under 2,000 and then use the minimum pedal position required to maintain speed. This will probably require slower speed than what you're used to.

Your aerodynamics are fine. The problem is rpm. If you get up to higher speeds, the engine is running too fast to be efficient. If you could keep below 50 km/h you'd do even better.

I did a few traction test’s on snow with my “All season” tires.
I feel I got a good idea of PSI/Traction/All-Season tires. (for my car and tires)

I have a feeling Snow tires traction should fall into the same results, (just all around better, lol)

Before testing I had thought low PSI was better for traction.
Low is bad,
High is bad,
Someplace around Tire listed Max is best.

http://www.cleanmpg.com/forums/showthread.php?t=17966&highlight=traction

For that long climb, aim for rpm under 2,000 and then use the minimum pedal position required to maintain speed. This will probably require slower speed than what you're used to.

Your aerodynamics are fine. The problem is rpm. If you get up to higher speeds, the engine is running too fast to be efficient. If you could keep below 50 km/h you'd do even better.

The car is geared well for FE. At 90km/h (56mph) in top gear the engine is at 2000rpm. Is that still a good speed for the climb?

At 100km/h (62mph), which is the highway limit in Ontario, the engine is at 2200rpm. 105km/h (65mph) = 2300rpm. Is 105 a reasonable cruising speed for FE? Would there be much difference between 105 and 90?

The usual flow of traffic is at least 120km/h (75mph). I prefer 105 instead of 100 because they recently passed legislation requiring a 105km/h speed limiter on all heavy trucks in Ontario, so I'll be less likely to have trucks riding my bumper. We're still in the speed limiter grace period though, so there are still trucks regularly passing me at 105.

I'm definitely gliding better with these new tires at 44psi. I'm also getting more used to the distance I can glide and I'm getting better at DWB. Before coming to this site I used to engine brake instead of glide because I'd heard about fuel injector shut-off. I'm gliding now.

On the last tank though, I caught myself accelerating using the BSFC chart and then immediately catching a red light or having traffic stop. Only 37.5MPG as a result.

I think I'll go back to accelerating slowly in the city so that I avoid more red lights and other peoples' braking. On the highways or if it's wide open ahead I'll accelerate at 70% load.

I'm also going to try out going the speed limit of 80km/h instead of 90 on the highway here. Most of my driving is on that.

Does anybody have any other suggestions?

Don't give up on the better acceleration rate -- concentrate instead on maximizing your glides. You can do this by getting up to a sufficient speed earlier and gliding longer.

Here's a key point that took me a while to really understand.

Aim to end each glide with a higher average mpg than the previous. The magic happens in the glide, not so much in the pulse. The nuance to this is not to try and keep the pulse short, to reduce the Ampg hit. Do whatever pulse is needed for the conditions, but then stretch the glide out longer to achieve the gains.

The best cruising RPM is the lowest one you can stand. In very large part, that's because lower RPM (given you're in top gear) means lower speed. Of course, it takes longer to get where you're going at lower speeds, and it can lead to antisocial behavior on the part of drivers around you, so you will have to balance those factors and your comfort level against the MPG gains.

-soD

Here's a key point that took me a while to really understand.

Aim to end each glide with a higher average mpg than the previous. The magic happens in the glide, not so much in the pulse. The nuance to this is not to try and keep the pulse short, to reduce the Ampg hit. Do whatever pulse is needed for the conditions, but then stretch the glide out longer to achieve the gains.

So if my next pulse will be cut short by a hill, is it best to DWL past the hill and then P&G when it's flat again?

Also, I've tried FAS and bump starting for the past week or so and I'm not sure about the wear on the car. I do it very carefully but there's a klunk noise in the exhaust when I bump start sometimes (it makes the same noise using the starter every time) so to minimize the abuse I should probably avoid it. The car just needs to last me another year or two (to 250,000km), and if I can get through that with the original clutch and exhaust system I'll be happy. :)

Unless I'm doing it wrong. When I bump start I've been using 5th gear, just jabbing the clutch out for an instant and back down. When I FAS I've been waiting for the engine to go down to 1100rpm but by then, 25% or more of my glide is gone. My thought is that it's better to stop an engine as close to idle rpm's as possible but I'm not sure if it makes a difference.

It sounds like your glides are too short, if waiting that second for the rpm to stabilize is a quarter of your glide. I aim for 10 seconds minimum. There is one place on my commute with a nice gradual downhill where I can sometimes glide for a mile. Of course, the return trip is a bear. DWL for that.

If you have a hill coming up, DWL up it at the best speed. See your chart above for that. Then, start your glide before the peak so you drop speed and then start regaining speed on the downhill slope.

I also let the rpm drop down to idle before turning the key. You leave it keyed off for less time that way.

It takes more like 3-4 seconds for my engine's rpm to drop to idle. I don't know why but I guess it's longer than most. I'll pulse, and as I finish lifting off the gas I push the clutch.

Also, when I switch the ignition back to ON, the gauges all do a needle sweep. It's not a standard feature, it just started doing it a few years ago. I lose the speed indication for a few seconds there.

I'm new here this is my first post. I have a 08 yaris and would like to know the way to get better mileage with a 5 speed thanks ,mark.

Mark, read the Beating the EPA article stickied at the top right of the home page here. The best thing you can do for mileage is slow down. You can see an instant mileage improvement of 30-50% by slowing from 72 mph to 55 mph.

It takes more like 3-4 seconds for my engine's rpm to drop to idle. I don't know why but I guess it's longer than most...

Mine is the same way, but about 2 seconds.

Well I finished off a few more tanks with good results. I'm still not using P&G, but I have been FASing and gliding up to stops, speed limit drops and some hills.

I had two tanks at 52 MPG UK, which is the peak number I got last summer. Last summer I used engine braking instead of coasting, no FAS, minimum rpm ~1500 (~1000 now), and taking a less efficient route.

One tank I had the AC on most of the time and drove the old route at the flow of traffic with no FAS. Ended up with 49 MPG UK.

The old route is a 4 lane undivided 80km/h road with sensor driven traffic lights. In the morning there are usually very few stops and light traffic. In the afternoon there are a lot of stops and other bottlenecks in the city to deal with. I still go this way in the morning.

The new route is back roads, half 60km/h limit and the rest 80km/h. Very light traffic, few lights and no bottlenecks to deal with. In the morning, this route takes 5 minutes longer which I don't usually have. In the afternoon though, it's at least 5 minutes faster than the other way because of the lack of traffic.

I'm hoping to top 60 MPG UK in the coming months.

Out of curiosity, does anyone know when the summer/winter gas changeovers occur in Canada?